前沿文献阅读.docx

An Overview ofnanoscale zero-valent ironMore recently, because of my research requirements, I need to read some papers about zero-valent iron, which are searched from China National Knowledge Infrastructure(CNKI) or Google Books. The following are some of my readings and notes.IntroductionZero-valent iron (Fe0(s) or ZVI) has been used to remediatea variety of contaminants. In particular, reductive reactionsof ZVI have been employed in permeable reactive barriersto remediate groundwater contaminated with halogenatedsolvents and reducible inorganic contaminants. Nanoscalezero-valent iron (nZVI) has been suggested an alternativemeans of exploiting the reactivity of ZVI without theneed to construct passive barriers. The main advantages ofnZVI are its high reactivity and the potential for introducingthe particles directly into contaminated soil and groundwater.Thepreparation of nanometer zero-valent ironThe preparation of nanoscale zero-valent iron in general can be divided into physical method and chemical method.Evaporation condensation methodAlso called low condensation method. It is introduced in super vacuum evaporation indoor low pressure inert gas (helium or argon), heating the metal iron, gasification vaporizes atomic fog, fog atomic collisions with inert gas quantity lost again, and nanoscale iron particles is formed afterquenching. In high vacuum evaporation cavity ventilation with high purity, with metalmolybdenum as heat source of metallic iron heating evaporation, then the particle surface passivation of for a long period of time. Thus made of iron nanoparticles are spherical, the average particle size was, and stable performance in the air, no further oxidation.Liquid phase reduction methodLiquid phase reduction method is the most commonly method used in thepreparation of nanometer zero-valent iron, but the current preparation process isdifficult to abtain clean and dry nanometer zero-valent iron. Material, especially thesurface of material usually contain